The chicken is a domesticated species that arose from the red junglefowl, originally from India. They have also partially hybridized with other wild species of junglefowl (the grey junglefowl, Ceylon junglefowl, and green junglefowl).[ Rooster and cock are terms for adult male birds, and a younger male may be called a cockerel . An adult female bird is called a hen , and a sexually immature female is called a pullet. Humans keep chickens primarily as a source of food (consuming both their meat and eggs) or as pets. Chickens domesticated for meat are broilers, and for eggs, they are layers.